In a report released on Wednesday, the US marshall general said that a US drone strike killed al-Awlaki in Yemen on September 12.
The report was issued after the US Department of Justice, under the Obama administration, declined to prosecute the former US citizen.
Al Jazeera’s James Bays, reporting from Washington DC, said the report revealed some disturbing details about the US drone programme.
Al-Awlani, the deputy leader of the al-Qaeda-linked Islamic State group, was killed on October 30, the marshal said.
“There is a lot of evidence that he was a senior planner, an advisor to al-Qaida and a close associate of al-Zawahiri, the Yemeni-born cleric,” he said.
The US has conducted dozens of drone strikes in Yemen since it launched the operation against al-Qa’ida in the Arabian Peninsula (AQAP) in the country in late 2014, killing hundreds of militants.
The drone programme is widely seen as a vital part of the US strategy against al,Qa’,ida, but the US government has repeatedly denied any links to the group.
Al Qaeda’s chief in Yemen, Osama bin Laden, has been living in the US for the past 25 years, but al-Wahhab, the group’s leader in the south, is considered a fugitive and subject to a US arrest warrant.
Al Awlaki was reportedly arrested in 2014 and imprisoned by the US on charges of conspiring with the US to carry out the 9/11 attacks.